1. Field of the Invention
The present invention relates generally to the field of molecular diagnosis. More particularly, it concerns the use of induced pluripotent stem cells (iPS cells) in determination and characterization of genetic variation.
2. Description of Related Art
Pathology caused by defects in human genes is usually highly tissue-specific. In heritable diseases, this suggests that specific spatiotemporal functions of the implicated genes are disrupted due to germ-line mutations. Although it has been shown that disease genes generally tend to be expressed in a limited number of tissues, it is still unclear in many cases how the tissue-specific expression patterns or genetic structure of disease genes correlate with their pathological or abnormal manifestations, and it remains difficult to determine or characterize the abnormal genes or genetic structure in certain tissue or cell types.
In a broader aspect, understanding genetic variation is a key goal of human genetics, encompassing disease susceptibility, variable response to drugs and ultimately treatment and public health.
The human body is assembled from more than 200 cell types present in a variety of tissue types. For identifying unknown genetic defects or determining genetic variation, specific cell types need to be isolated and characterized. However, some cell types may be hard to obtain from a human subject in vivo, such as the highly specialized retinal pigment epithelium (RPE) cells. Thus, there remains a need to develop more convenient methods to provide specific cell types to analyze the tissue-specific genetic variation.